(1) Field of the Invention
The present invention relates to lighting apparatuses mainly with LEDs (Light Emitting Diodes), and more particularly heat removing methods for such lighting apparatuses.
(2) Description of the Related Art
Lately, lighting apparatuses with LEDs have been attracting attention as next-generation lighting apparatuses to take over fluorescent lamps and the like. The lighting apparatuses with LEDs have advantages in compactness and a long life span over incandescent lamps, fluorescent lamps and mercury lamps.
LEDs, however, do not have very high luminous efficacy presently and a large part of electricity supplied to LEDs turns into heat. There are problems that the heat reduces the quantity of light from the LEDs, or in a worst case, the heat damages the LEDs.
In order to solve the problems, there is an idea to install a heat sink on the back of a substrate on which LEDs are mounted; however, with this idea one of the benefits of the LED lighting apparatuses of being compact would be lost, because a cooling member needs to be installed as well as another device for dissipating the heat conducted to the cooling member.